Edward m



UNITED STATES PATENT OFFICE.

EDVARD M. BENTLEY, OF WASHINGTON, DISTRICT4 OF COLUMBIA.

ELECTRIC WAY.

SPECIFICATION forming part of Letters Patent No. 276,954, dated May 1, 1883.

Application tiled March 27, 1883.

a system to be used in the vicinity otl disturbing wires. It is fully illustrated in the accompanying drawings, wherein- Figures l, 2, 3, and 4 represent cables embodying my invention. Fig. 5 represents a core made up of several parallel wires. Fig. 6 represents a diagram ofthe manner ot' their use in a system.

C represents the core ot' the cable, which may be simply a rope or rod ot' insulating material, as in Figs.3 and 4, or may be composed ot' an insulated wire, as shown in Fig. l, or several wires, as shown in Figs. 2 and 5. Around O, Fig. 1, are wound in substantially parallel helices the direct and return wires D and It of an electric circuit, they being insulated in any manner, either before heilig wound on the core or by being embedded in the material of the core itself. It will be seen that D and It, being thus wound, have always the saine relative position to any external wire as A, and neither affect it inductively nor are attected by it. It will also be seen that they are similarly situated with respect to an in'- ternal wire, T, so that the core can be made up of such wires, and they will all be inductively independent of the wires D and It. In Fig. 1, D and R represent a telegraph-circuit, and T a telephone-wire; but this arrangement may be reversed, as shown in Fig. 2, or any other electrical translating; devices used on the various circuits. Vhere G is made up ot' insulated wires they may be a simple bundle ot' straight parallel wires, as shown in Fi 0. 5; or

' a number ot' wires, T, may be wound on a core,

c, and the whole then serve as a core upon which wires D and It may be wound. This arrangement is illustrated in Fig. 2.

(No model.)

As thus far described, the invention provides for but one direct and return circuitin a cable. Any number of direct and any number of return circuits may, however, be used. In Fig. 3 are shown t'our direct circuits, each provided with a battery, transmitter, and receiver, and one common return circuit therefor, two direct being on each side ot' the common return. In Fig. a there are six direct aud two return circuits. Any number ot' wires may be used as direct circuits and any number as return circuits. For telegraphic purposes, where the quantity ot' electricity to be carried is small, and on long lines, where the common return is only run a short distance, as to the edge of the city or outside the area of inductive disturbance, one common return can be used for a number ot' direct circuits. It can be used with a still greater number it' the batteries on one halt' of the direct circuits have their positive and the other half their negative plates connected to the common return, as shown in Fig. 3. I do notclaim this arrangement of batteries.

In the diagram Fig. 6, D and B represent, respectively, the direct and common return circuits i'or trunl: lines starting from the central office, O, and ruiming along the main street of a city and ott to a distant station. D and R represent the direct and common return circuits used for local business and starting from the same central otlice. It is to be understood that they are all running in the vicinity ot' other disturbing wires, more especially in the manner set forth in a pending application ot' even date herewith filed by myself as joint inventor with \Valter H. Knight. Thev common return R ot' the through lines is grounded outside the city limits or the area of inductive disturbance ot' light and telephone wires. Its resistance compared with the total length of the through-line wires is therefore very small, although it may be small in cross-section, and the effect will be the same as it' all the through lines were grounded at the central otce. The local lines are not grounded at all, but all return through the common wire It. L is a loop of a local line passing through the stations c, 11,0, and d, and as at each point ot'- the loop there is a direct wire accompanied by its corresponding return IOO wire, it is anti-inductive to any line in its vicinity. L is a second loop going through stations @,f, and g. This loop is anti-inductive only from h to r, a single circuit going completely around the block J. M and N are substations connected with the central ofce by several wires, which are in each case accompanied by the common return.

The advantage of this system is that by the addition of a small number of Wires for returns existing systems can be rendered inductively independent of other wires whereve it is necessary, no change in or addition to the present instruments heilig required. As no telegraph-wires are grounded in the city, there will be no danger ot' telephone-Wires berng disturbed by branch currents from grouud-plates, which is considered one of the most prolific sources ot' telephone disturbance.

I hereby reserve the right to claim more completely the system and other matters herein shown 0r described, but not claimed, in subsequent applications.

Vhat I claim as my invention isl. The combination ofthe direct and return limbs of an electric circuit, Wound on a conducting-core' made up of one or more single limbs of an electric circuit.

2. rl`he combination of several direct conductors and one or more common return conductors therefor, each direct conductor and the common return conductor or conductors being practically equidistant from any neigh` boring parallel conductor.

3. The combination ot' several direct conductors, forming distinct circuits, and a common return therefor, the Whole arranged in anti-inductive relation to neighboring parallel circuits.

4. The combination of several direct conductors and one or more return conductors theret'or, the Whole arranged in anti-inductive relation to neighboring parallel circuits, thc return conductors being arranged symmetrically between the direct conductors.

5. The combination of several direct coilductors and a common return therefor with neighboring disturbing wires, the return conductor being` grounded outside the area of inductive disturbance.

6. The combination ot' several direct couductors, forming portions ot' independent circuit-s, and a common return therefor, with loopcircuits taken from the direct conductors, as described.

7. The combination ot several direct conductors and a common return therefor of a branch from the common return, serving as a return forone or more ot' the direct conductors.

ED TARD M. BENTLE Y.

Witnesses:

WM. S. SAYERs, HERBERT KNIGHT. 

